The invention relates to a clutch disc for a motor vehicle friction clutch.
A clutch disc for a friction clutch of a motor vehicle is known from Fed. German Publ. Spec. No. 31 21 376. The clutch disc comprises a hub from which a hub disc protrudes radially. Axially on both sides of the hub disc, side discs connected fixedly with one another into a unit are mounted for rotation through a limited angle on the hub. One of the side discs carries the friction linings of the clutch disc. Several damping springs are arranged in windows of the hub disc and the side discs and are subjected to compression stress on relative rotation of the hub disc and the side discs. The clutch disc comprises an under-load friction damper dimensioned for under-load operation of the internal combustion engine of the motor vehicle and an idling friction damper dimensioned for idling operation. The under-load friction damper has a single control disc arranged axially between the hub disc and one of the side discs and co-operating in the usual way with one of the damping springs such that it accompanies the relative rotation of hub disc and side disc only after overcoming a certain idling rotation angle. The control disc forms one of the friction faces of the under-load friction damper and is initially stressed by a dished spring through a friction ring against the adjacent side disc. The dished spring is supported on the one hand on the other side disc and on the other hand on tabs of the control disc which engage axially through openings of the hub disc. The idling friction damper is arranged together with the dished spring of the under-load friction damper radially within the region of the clutch disc which is radially enclosed by the tabs.
In the known clutch disc the dished spring of the under-load friction damper is supported directly on the side disc. This increases the wear both of the side disc and of the dished spring. Furthermore the tabs passing through the hub disc are irregularly stressed in the circumferential direction of the control disc. The control disc and its tabs must therefore be comparatively stoutly dimensioned.
From German Utility Model No. 75 38 331 a further clutch disc is known in which between side discs, arranged axially on both sides of the hub disc and connected with clutch friction linings, on the one hand and the hub disc one the other, there are arranged two control discs which co-operate each with different damping springs and are connected with one another to form a unit by rivets passing through openings of the hub disc. The idling friction damper of this clutch disc is seated axially outside the side discs. The clutch disc of this construction type has relatively large dimensions in the axial direction.